This was published in the Cochrane Database of Systematic Reviews in September 2016. The full text of this review is available via this link

Review question. We evaluated the evidence about whether people with abnormal coagulation (poor blood clotting) require a plasma transfusion prior to insertion of a central line (central venous catheter (CVC)), and if so, what is the degree of abnormal coagulation at which a plasma transfusion is required.

Background People with abnormal coagulation often require the insertion of central lines. Central lines are catheters whose tip usually lies in one of two main veins returning blood to the heart. They have a number of uses including: intensive monitoring and treatment of critically-ill patients; giving nutrition into a vein (when the patient cannot eat); giving chemotherapy or other irritant drugs with fewer complications; and when patients require long-term repeated treatments in to a vein. Current practice in many countries is to give plasma transfusions to prevent serious bleeding due to the procedure if blood tests to assess clotting are abnormal. The risk of bleeding after a central line insertion appears to be low if the clinician uses ultrasound to guide insertion of the line. Correction of clotting abnormalities with fresh frozen plasma (FFP) is not without risks of its own, and it is unclear whether this practice is beneficial or harmful. People may be exposed to the risks of a plasma transfusion without any obvious clinical benefit.

Study characteristics The evidence is current to March 2016. In this review we identified four randomised controlled trials, three trials are still recruiting participants and are due to complete recruitment by February 2018. The completed trial (58 participants) compared plasma transfusion to no plasma transfusion prior to central line insertion.

Key results There was not enough evidence to determine whether plasma transfusions affected minor or major procedure-related bleeding. The included study did not report the number of people dying due to any cause, the number of people receiving red cell or plasma transfusions, the occurrence of transfusion or line-related complications, length of time in hospital, correction of clotting abnormalities, or quality of life.

Quality of the evidence The quality of the evidence is very low because this review includes only one small study.

Authors’ conclusions: There is only very limited evidence from one RCT to inform the decision whether or not to administer prophylactic plasma prior to central venous catheterisation for people with abnormal coagulation. It is not possible from the current RCT evidence to recommend whether or not prophylactic plasma transfusion is beneficial or harmful in this situation. The three ongoing RCTs will not be able to answer this review’s questions, because they are small studies and do not address all of the comparisons included in this review (355 participants in total). To detect an increase in the proportion of participants who had major bleeding from 1 in 100 to 2 in 100 would require a study containing at least 4634 participants (80% power, 5% significance).